A catastrophic tank failure at a paper mill on the banks of the Columbia River has killed eleven workers, sent hundreds of thousands of gallons of caustic industrial chemicals toward a waterway that tribal nations have depended on for centuries, and left Indigenous leaders demanding transparency from the company responsible.
The rupture occurred May 26 at the Nippon Dynawave mill in Longview, Washington, where a tank holding “white liquor” — a highly caustic chemical used in pulp processing — gave way and released close to 600,000 gallons of the substance. The disaster stands as one of the deadliest industrial accidents in the Pacific Northwest in recent memory.
Chemical Path to the Columbia
After the tank failed, an unknown quantity of white liquor entered the mill’s drainage infrastructure, which connects to a broader network of industrial ditches serving the surrounding area. Emergency responders made the decision to flush those ditches into the Columbia River as a strategy to dilute the chemical concentration and protect municipal drinking water supplies downstream.
State officials recorded elevated pH levels in the ditch network during the first day following the rupture. Separately, Nippon’s own monitoring systems detected two pH spikes from pumps transferring ditch water into the river — both times the pumps automatically shut down when the spikes were detected.
The biological toll in the ditch system has been substantial. Nearly 3,000 dead fish have been recovered from the ditch network since the rupture, losses attributed to the initial surge of caustic chemicals through that waterway. State authorities subsequently conducted 72 consecutive hours of pH monitoring with no elevated readings before declaring the ditch system clear of active contamination.
A company spokesperson said that while some chemical did enter the Columbia, the river’s volume and current speed worked in the cleanup effort’s favor, estimating the dilution took place over roughly the length of a football field from the point of entry. Officials emphasized that dilution does not equal zero impact, and monitoring of the main river channel continued.
Treaty Rights and Tribal Voices
For the tribal nations whose relationship with the Columbia River predates any mill, pipeline, or dam, the spill carries weight beyond environmental cleanup metrics. The 1855 treaty signed between the U.S. government and several Columbia River tribes explicitly preserved tribal members’ right to fish at their usual and accustomed places along the river and its tributaries — a legal foundation that has sustained Indigenous fishing culture for more than 170 years.
Warm Springs tribal chairman Dennis White III used the occasion to call for full transparency and accountability from Nippon Dynawave. He framed the tribe’s stake in the river not as an interest to be weighed against industrial activity, but as an identity inseparable from the water itself.
“We are river people,” White said in remarks following the spill. “We come from the Big River. Our river is a way of life, and water is life.”
White’s statement reflected a broader concern among tribal leaders that industrial operations along the Columbia continue to pose risks to a resource that tribal communities depend on both culturally and as a source of subsistence. The Warm Springs and other Columbia River tribes have long maintained that when the river is harmed, their way of life is harmed — a position grounded in treaty law and reinforced by the scale of this week’s contamination event.
The fish kill in the ditch system, while separated from the main river channel, underscored what happens when industrial chemicals enter aquatic environments even briefly. For tribes whose treaty-protected fishing rights depend on healthy fish populations, the loss of nearly 3,000 fish — even in an industrial ditch — serves as a visible marker of what broader contamination could mean.
What Comes Next
State and federal environmental regulators are expected to continue monitoring the Columbia River and surrounding drainage systems in the weeks ahead. Questions remain about the total volume of white liquor that entered the drainage network, the long-term effects on fish and aquatic habitat in the ditch system, and what regulatory consequences Nippon Dynawave may face following the accident.
Tribal leaders have indicated they will remain engaged in the oversight process, pressing for public disclosure of all monitoring data and accountability for any violations of environmental or treaty obligations. The 1855 treaty, upheld repeatedly in federal courts, gives tribal nations legal standing that environmental regulators and the company will need to address as the investigation continues.
For Idaho communities along the Snake River — a major Columbia tributary — events like the Longview spill serve as reminders of how interconnected the river system is and how far upstream consequences can reach. More information on Idaho water and environmental news is available at idahonews.co.